This invention pertains to harvesters and in particular to harvesters useful in the harvesting of the crop sorghum. Sorghum is a globally important plant as numerous sorghum species are used for food, fodder, the production of alcoholic beverages, and biofuels.
More specifically, sorghum is used as a staple of human nutrition all over the world. Globally, over half of all the sorghum used is used for human consumption. Sorghum, especially sweet sorghum, is a major crop for many farmers especially in the continents of Africa, Central America, and Asia. The grain from sorghum can be used for flours, porridges, distilled beverages, and specialty foods.
Sorghum is also a significant crop for feeding animals. In the United States, sorghum is used primarily as an animal feed; however, other uses are being developed constantly for this plant by a variety of industries. Sweet sorghum is also quite suitable for silage. Silage is fermented, high-moisture fodder which can be fed to cud-chewing animals such as cattle and sheep. Sorghum is fermented and stored in a process called ensilaging and is usually made from using the entire sorghum plant, not just the grain.
Sorghum can also be used in the textile industry for manufacturing wallboard, fences, biodegradable packaging material, and solvents. Dried sorghum stalks are often used for cooking fuel and die can be extracted from the plant for coloring textiles such as leather. More recently, sweet sorghum has been used to produce ethanol. Byproducts from ethanol production, such as sorghum-DDGS (distillers dried grains with solubles), are also finding a place in the global market.
Typically, wild sorghum is a tall plant ranging from 5 to 7 feet in height. Sweet sorghum has been bred to grow 8 to 15 feet tall. As discussed above, all parts of the sorghum plant provide useful purposes. The two most important structures of the sorghum plant are the grain head and the stalk.
Globally, the top sorghum producing countries are the United States (approximately 17% of global production), Nigeria, India, (each with approximately 14% of global production) and Mexico (approximately 11% of global production). Given the vast importance of this crop to the world, a need exists to efficiently and effectively harvest all parts of the sorghum plant in a single-filed pass.
The concept of a combine harvester, or simply a combine, is well known in the prior art. The combine harvester was invented in 1834 and early versions were pulled by horse or mule teams. In the early 1950s, the first self-propelled combine harvester was manufactured and it was capable of harvesting up to 5 tons of wheat a day. The self-propelled combine is still in use today and is typically powered by diesel or gasoline engines. In spite of all of these advances, however, the combine harvester has remained largely the same. Accordingly, even modern harvesters are unable to simultaneously harvest the grain tops and stalks of important plants such as the sorghum plant.
There has been a growing need to provide a harvester which can simultaneously harvest all portions of a plant in a single pass of a field. Thus, since different portions of a plant may be used for different industries, there is a growing need to provide a harvester which has the ability to cut various portions of a plant, sort those portions, and then transport those portions in an independent manner for individual users.